A session is established after the database accepts the username, password, and account number and returns a session number to the process.
Subsequent Teradata SQL requests generated by the user and responses returned from the database are identified by:
The database supplies the identification automatically for its own use. The user is unaware that it exists.
The context for the session also includes a default database name that is often the same as the user name. When the session ends, the system discards the context and accepts no further Teradata SQL statements from the user.